2010 Denali/Mileage Question

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rdezs

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I'll add the vehicle runs perfectly the tires are inflated properly and transmission is in good working condition, spark plugs/wires have about 10k on them or less and I use 93 octane
.... So something's definitely off. We use 92 octane on long road trips, like the 900 miles to Vegas and it nets us 20 MPG. I'm wondering if you're getting close to having the catalytic converters plugged. Maybe not enough yet to set the code. How old is the muffler? Did the plugs look good when you changed them? Wouldn't hurt to plug in and check the fuel tables and such...
 

Foggy

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My 14 on the window sticker says 13mpg city/ 18 mpg highway.
That's certainly a pipe dream of the OEMs.. as that's tested at ideal conditions
on a NEW vehicle. When I was totally stock I got 17.2 hwy. With DOD just
disabled I got 17.0 !!!!
So if your driving in urban/suburban traffic 13 is pretty normal ish
Do the maint as suggested above and make sure your tires and alignment
are "right"
 

wjburken

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My wife’s 2013 Denali XL averages between 14 & 15 mpg. She does a fairly even mix of highway and city.

This is right online with what we got on our 2007, 2008 Denali XL’s and our 2009 Suburban.
 

Doubeleive

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.... So something's definitely off. We use 92 octane on long road trips, like the 900 miles to Vegas and it nets us 20 MPG. I'm wondering if you're getting close to having the catalytic converters plugged. Maybe not enough yet to set the code. How old is the muffler? Did the plugs look good when you changed them? Wouldn't hurt to plug in and check the fuel tables and such...
Cats are new less than a year old each, it's none of the above, it's just how I drive. I can take a brand new one off the lot and get the same mpg
 

petethepug

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2010 YXL Denali with fire breathing 6.2L?

13 MPG is good. Did you end up transporting it or flying out to get it?

Your milage is great. 2011 may have an instant milage calculator and average trip calculator. If you want to know what highway mileage is just reset the milage calculator while you’re at highway speed.
IMG_2702.jpeg

 

rdezs

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That sounds about right, driving it normally. It's also a pretty good indicator on the condition of the engine in general
 

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